This invention relates to an apparatus for making packaging sleeves from sheet blanks. Each blank is folded about a mandrel and the overlapping edge zones of the blank are pressed and bonded to one another and subsequently the obtained packaging sleeve is stripped from the mandrel. Such an arrangement, which provides a longitudinal seam on the packaging sleeves has been long known. After stripping the bonded sleeve from the mandrel, the sleeve is advanced to stations of a packing machine.
According to a known arrangement of the above-outlined type, such as disclosed, for example, in U.S. Pat. No. 3,530,773, the operational phase including the stripping of the packaging sleeve from the mandrel is particularly circumstantial because the tools (such as pliers or the like) used for stripping can damage the sleeve which firmly surrounds the mandrel, since these tools engage only a relatively small portion of the sleeve and thus exert a large local force thereon. This difficulty is often increased by the fact that excess quantities of the adhesive may solidify on the mandrel and thus the adhesion of the sleeve to the mandrel is further increased.
A further disadvantage of known arrangements of the above-outlined type resides in their slow operation because of a waiting period between forming the sleeve and removing it from the mandrel to allow setting of the adhesive to ensure a satisfactory bond between the overlapping edge zones of the packaging sleeve.